Brachiopod Fossil with Tentculites A.jpg
Brachiopod Fossil, with Tentaculites
SITE LOCATION: West Virginia
TIME PERIOD: Devonian Period (over 350 million years ago)
Nicely detailed small Devonian brachiopod from West Virginia as well as several tentaculites impressions. Brachiopods, phylum Brachiopoda, are a group of lophotrochozoan animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs.
Tentaculites is an extinct genus of conical fossils of uncertain affinity, class Tentaculita, although it is not the only member of the class. It is known from Lower Ordovician to Upper Devonian deposits both as calcitic shells with a brachiopod-like microstructure and carbonaceous 'linings'. The "tentaculites" (i.e. tentaculita) are also referred to as the styliolinids. The taxonomic classification of tentaculitids is uncertain, but some group them with pteropods. They may also be related to other conical shells of uncertain affinity including cornulitids, Anticalyptraea, microconchids and trypanoporids. Their shell microstructure has warranted their comparison with the brachiopods and phoronids. Tentaculitids have ribbed, cone-shaped shells which range in length from 5 to 20 mm. Some species septate; their embryonic shell, which is retained, forms a small, sometimes spherical, chamber. Classification below is for both animals, and is split.
Phylum: Brachiopoda/Mollusca (?)